The invention pertains to methods of forming hafnium-containing materials, such as, for example, hafnium oxide. The invention also pertains to capacitor constructions comprising hafnium oxide.
Hafnium oxide can have appropriate physical properties to be useful as a dielectric material in integrated circuitry. Specifically, if hafnium oxide has a tetragonal (also referred to as tetraclinic) crystallographic orientation, or an orthorhombic crystallographic orientation, it can have appropriate permittivity and low leakage to be suitable for utilization as a dielectric material in numerous circuit devices, such as, for example, capacitor constructions. However, if the hafnium oxide is in a monoclinic crystallographic orientation, the hafnium oxide can have a leakage current which is too high to be suitable for utilization in integrated circuit devices. The leakage of monoclinic hafnium oxide is typically about 10xe2x88x927 amps/cm2, while the leakage of tetragonal and orthorhombic hafnium oxide is typically about 10xe2x88x929 amps/cm2.
It would be desirable to develop methods by which hafnium oxide can be cost-effectively and reliably formed in a non-monoclinic crystallographic orientation (such as, for example, a tetragonal or orthorhombic crystallographic orientation). It would be further desirable if such methodology could be extended to other hafnium-containing materials besides hafnium oxide. Additionally, it would be desirable for the methodology to be extendable to integrated circuit device fabrication processes.
In one aspect, the invention pertains to methods of forming hafnium-containing materials. A semiconductor substrate is provided. First reaction conditions are utilized to form hafnium-containing seed material in a desired crystallographic orientation over the substrate. Subsequently, second reaction conditions are utilized to grow second hafnium-containing material over the seed material. The second hafnium-containing material is in a phase and/or crystallographic orientation different from the hafnium-containing seed material. The second hafnium-containing material can be, for example, in an amorphous phase. The seed material is then utilized to induce a desired crystallographic orientation in the second hafnium-containing material.
In one aspect, the invention pertains to a method of forming hafnium oxide. A first hafnium oxide-containing material is formed over a substrate, with the first hafnium oxide-containing material being predominately in a crystalline phase having a tetragonal orientation. A second hafnium oxide-containing material is formed over the first hafnium oxide-containing material, with the second hafnium oxide-containing material being in a substantially amorphous phase. The first hafnium oxide-containing material is then utilized to induce the crystalline phase having the tetragonal orientation in the second hafnium oxide-containing material.
In one aspect, the invention includes a capacitor construction. The construction includes a semiconductor substrate, and a first capacitor electrode over the substrate. A dielectric material is over the first capacitor electrode, and a second capacitor electrode is over the dielectric material. An entirety of the dielectric material between the first and second electrodes consists essentially of hafnium oxide in a crystalline phase and having a non-monoclinic crystallographic orientation. In particular aspects, the hafnium oxide can have a tetragonal crystallographic orientation. The capacitor construction can be utilized in, for example, DRAM constructions, and such constructions can be incorporated into electronic systems.